Key points here are that it's compiled for ARMv7 and ARMHF, so should be faster than the Raspbian image by some amount. And it'll have more recent versions of software because that version of Ubuntu is significantly newer than Debian Wheezy!

as the image is, if you use your micro-sd card in more than one RaspberryPi2, udev will change eth0 to eth1 based on the new LAN MAC address (this is disabled in raspbian) which will cause any static IP addresses assigned to eth0 to not be assigned (there will be no eth0)